Fire-alarm and telephone system



L t e e h S 8 .L e e h S 2 0 L D U L S m. d o M o m FIRE ALARMAND TELEPHONE SYSTEM.

PatentedApr. 14, 1891.

I77 V5.77 far W 0, M

1 UNITED STATES PATENT OFFICE.

SAMUEL w. LUDLOW, or MADIsONvILLE, 01110.

FIRE-ALARM AND TELEPHONE SYSTEM.

SPECIFICATION forming part'of Letters Patent No. 450,245, datedApril 14, 1891.

Application filed July 12, 1890. Serial No. 358,486. (No model.) I

To all whom it may concern.-

Be it known that I, SAMUEL W. LUnLoW, a citizen of the United States, residing at Madisonville, county of Hamilton, and State of Ohio, have invented certain new and useful Improvements in Fire-Alarm and Telephone Systems, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification.

My improvements relate to a combination of firfa rm and telephone systems, whereby an alarm of fire may be automatically communicated to the telephone-exchange through the medium of the ordinary telephone system of circuits without in any way altering said system or afiecting the ordinary telephonic intercommunication between the telephone exchange or station and the subscribers and users.

' My invention is intended to utilize the ordinary telephone system for sending in an alarm of fire automatically, so that the subscriber may use the telephone as at present; but should a fire break out on his premises in hisabsence the telephone-exchange will be automatically notified through the medium of the same circuit which at all times connects his premises with said exchange. I accomplish this result by a new construction and arrangement of parts, whichwill be here inafter more particularly pointed out and claimed. It will be obvious, however, that the particular devices used for determining the presence of fire may be any of the wellknown forms without departing from the spirit of my invention, which in the main consists in looping into the telephone-circuit an electrically-connected apparatus arranged to be set in action by the action of heat, so that the telephone-exchange may be notified, as at present, that there is a message to be communicated, and thereupon a transmitter may be automatically placed in circuit and a signal agreed uponsuch as the ringing of a bell-be conveyed audibly to the operator at the exchange, hearing which he may know that a fire is in progress on the premises of the subscriber.

My mechanism is intended to be applied to telephone apparatus such as is in use throughout the country, and to use the same character of generator, bell, and microphone as is now in use generally; but in order to avoid any interference whatsoever I provide supplemental telephone-instruments to be used for fire-alarm purposes in addition to the ordinary apparatus.

In the drawings, Figure lis a front view of my fire-alarm mechanism applied to the usual telephone apparatus, except that the call-bell is placed on the transmitter instead of the generator-box. Fig. 2 is aside view of the right side of same. view of. the opposite side of the generator-box. Figs. 4 and 5 are diagrammatic views of the ordinary telephone apparatus and my supplemental apparatus, showing the circuits and connections of my fire-alarm mechanism.

A is the base-board; B, the generator-box; O, the microphone-box, and D the battery-box as used in the ordinary telephone apparatus.

The construction of the generator within box B is such as is ordinarily in use in the Bell telephone apparatus, and my mechanism is intended to be applied thereto.

In the diagram Fig. 5, a represents the field-magnet, b the armature, and c the lever through which the various switching of circuits is made, and upon which the receiver is hung as ordinarily constructed. This lever c is in electric connection with the lineswire I, as shown in Fig. 5, and connection is made through the lever c by spring 1; and wire 2 to one side of the generator, and thence to the wire 3, which goes to ground.

In Fig. t is shown an ordinary telephone instrumentin which the circuit is closed, allowing a connection direct from line-wire 4, leading to the telephone-exchange, to the wire I, and hence the revolution of the armature in either the telephone-generator E or the generator B will send a signal to the exchange, which signal usually consists in dropping a shutter on the exchange switch-board giving the number of the telephone over which the call is being made. at is the shaft by which the armature of the generator is revolved, and upon this shaft is secured the ratchet-wheel 6. An ordinary coiled spring fis attached to this ratchet-wheel, so as to cause the same to revolve when the pawl g is released. This pawl g is weighted at h, and by means of the wire or line vi is in connection with the fire-alarm Fig. 3 is a side apparatus, so that the wire 1; will hold the pawl g in engagement with the ratchet-wheel until the heat breaks the connection of the wire 1', and allows the pawl g to drop into the position shown by dotted linesin Fig. 2, where it is held by stop to. Strips of metal adapted .to expand under heat may be placed along the ceiling or wherever else desired and the wire t' arranged to be held up by these strips until heat-say of 140 Fahrenheit-so expands the strips as to allow the wire to drop and thus release the pawl g, or the wire '& could be arranged to be dropped upon the melting of some proper substance, and thus release the pawl, or various other devices could be used to set in motion the ratchetwheel 6 by releasing the pawl. The usual crank j is used to wind up the coiled spring f, so that as soon as the pawl is released the ratchet-wheel, and with it the armature of the generator, will begin to revolve, and, as shown above, a signal will be sent to the exchange of exactly the same character as that sent by a subscriber when calling up the exchange. On the other end of the armature-shaft d is .the pinion 7a, which meshes with the gearwheel Z. Rigidly attached to this wheel Z is the arm m. An arm n, pivoted at its lower end to the box, is notched so. as to fit over the side of the lever c and hold itdown against the action of aspring within the box, which tends to raise the lever. The revolution of the pinion will, after a few revolutions, gaged' by the number of teeth of the pinion and wheel, bring the arm m into contact with the arm n, and, pushing it aside, allow the lever c to rise by reason of the action of spring 1;. This movement of the lever c breaks its connection with wire 2 through springs.

Within the generator-box B are the contact-points s, r, and t, which are not in contact with lever 0 when it is down, but upon the lever rising they are brought in contact therewith. In accordance with the usual construction of the Bell generators connections are made with these springs s, r, and from spring 8 to one pole of the microphone-battery, while the other pole of the battery is connected by wire 8 with the primary coil of the transmitter, the other end of which primary coil is connected by line 9 with spring r. Spring t is connected by wire 12 with the secondary coil of the transmitter and through this coil by wire 13 to the ground.

Upon thelever c is secured a teat o, of hard rubber or other insulating material, and above this teat are secured to the side of the box the spring 19 and contact-point not in connection with each other when the lever c is down; but when the lever c rises, forced up by spring 1;, the teat 0, coming in contact with spring 1), brings it into contact with the point g. This point (1 is in connection by wire 5 with wire 2, while spring 19 is connected by wire 6 with the coil in the box 0, used to operate the electric bell II, the other end of the coil connecting with the ground through wire '7. This electric bell is of the same construc* tion as that in use on the ordinary Bell-telephone generator; but instead of being placed on the generator-box, as usual, it is here placed on the microphone-box 0, so that the ringing of the bell can be heard more easily through the microphone. It will thus be seen from the above connections that raising the lever o breaks the line-circuit through the generator, but makes a local ground-circuit through the generator and electric bell, and also throws the transmitter into the line-cir cuit and completes the battery-circuit. It will therefore be evident that the moment the lever 0 is released and allowed to ris the electric bell 1-1 will begin to ring and t e transmitter will be thrown into the line-circuit, so as to convey the sound of the ringing bell to the operator, who, upon answering the call, instead of hearing the subscriber speaking, will hear the continuous ringing of the bell, and will thus know that there is a fire on the premises of the subscriber.

As I have already said, I do not wish to limit myself to the particular form of appa ratus shown, as it is evident that a signal could be arranged to be given to the exchange over the telephone-wires by many other de vices, which will be obvious to any one skilled in the art, and I do notlimit myself to a pawl and ratchet-wheel operated by a spring in connection with a series of wheels and lever to switch the transmitter into line-circuit.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

1. The combination, with a telephone-circuit and telephone apparatus consisting generator, transmitter, and battery, of means for automatically operating said generator upon an outbreak of fire, and mechanism for raising the switching-lever, so that the telephone-transmitter may be switched into the line-wire to convey a sound agreed upon as an alarm audibly to the operator at the telephone-exchange.

2. The combination, with a telephone-circuit, of generator, transmitter, battery, and electric call-bell, means for automatically operating said generator upon an outbreak of fire, mechanism for raising the switching-lever to throw the transmitter into circuit, and switches and connections to operate the electric bell simultaneously with the raising of the lever, substantially as shown and described.

3. In a combined fire-alarm and telephone apparatus, the combination of ratchet-wheel on the generator-shaft, pawl holding same till released by action of fire, system of gearwheels connected with said armature-shaft, and spring-actuated lever arranged to be released and to switch the transmitter and battery into line-circuit and the generator into local circuit with the electric bell, substantially as shown and described.

4. In a combined fire-alarm and telephone system, the combination, with the generator ter into the line-circuit and also to groundand switching-lever therein, of ratchet-Wheel circuit the electric bell, substantially as 10 on armature-shaft, spring to rotate same, shown and described.

pawl to hold the ratchet-wheel and armature- 5 shaft at rest until released by the effect of SAMUEL LUDLOW' heat, pinion on said shaft, gear-Wheel mesh- Witnesses: ing with same, and arm thereon to release ALFRED M. ALLEN,

said switching-lever and bring the transmit- GEORGE HEIDMAN. 

